1. Field of the Invention
Embodiments of the present invention relate to a semiconductor integrated circuit. More particularly, embodiments of the present invention relate to a system capable of providing a reference voltage to a semiconductor integrated circuit during reliability evaluation.
2. Description of the Related Art
In general, semiconductor integrated circuits may be employed to drive a variety of electronic devices. As a size of a semiconductor integrated circuit is decreased and its degree of integration is increased, power consumption thereof may increase. In part, the power consumption of the conventional semiconductor integrated circuit may increase during a reliability evaluation, e.g., burn-in test or a high-voltage margin evaluation, that may require a greater voltage as compared to a voltage required during normal circuit operation because of increased parasitic resistance generated during such evaluation. The parasitic resistances during conventional reliability evaluation of semiconductor integrated circuits may be generated by various parasitic components, e.g., resistance due to connection to a probe card, a contact, a printed circuit board (PCB), a test board, and so forth.
For example, a conventional semiconductor integrated circuit connected to a tester and having internal and ground voltage sources may include a first parasitic resistance between its internal voltage source and a voltage source of the tester, and a second parasitic resistance between its ground voltage and a ground voltage of the tester. Accordingly, a voltage difference between the internal source voltage and the internal ground voltage of the semiconductor integrated circuit may be lower than the voltage difference between the source voltage and the ground voltage of the tester. However, when a plurality of semiconductor integrated circuits are connected to a single tester, each such parasitic resistance may trigger different voltage drops in each one of the semiconductor integrated circuits due to variations in test conditions, current, and so forth. As such, each semiconductor integrated circuit may have a different voltage difference between the internal source voltage and the internal ground voltage, thereby minimizing uniformity of reliability evaluation of a plurality of semiconductor integrated circuits connected to the single tester.
Attempts have been made to employ an external reference voltage source, instead of the internal voltage source, during the reliability evaluation. However, such attempts have not provided for a constant internal ground voltage, thereby causing non-uniform voltage difference between the internal ground and source voltages. As such, uniform reliability evaluation of a plurality of semiconductor integrated circuits connected to a single tester has not been achieved.